Oil soluble dyestuffs



Patented Apr. 2, 1935 UNITED STATES PATENT OFFICE No Drawing.Application May 9, 1931,

Serial No. 536,313

Claims.

This invention relates to new dyestuffs, particularly dyestuffs whichare soluble in or may be readily dispersed throughout oils, fats, waxes,rubber solvents, and other bodies of similar na- 5 ture which as a ruledo not mix readily with water.

The invention also relates to a method of coloring materials of thenature described, and to a method of obtaining optically cleardispersions of dyestuffs and particularly water soluble dyestufisthroughout substances of the class described. There is a great need fordyestuffs susceptible to dispersion throughout oily or fatty bodies orliquids and the purposes of the dispersions form more or less underthree general headings: (1) Where it isdesirable to color an oily orfatty body of which colored motor fuels and colored paramn or stearicacid candles are examples; (2) For coloring a body or liquid of theclass described for the purpose of coloring some other material with itin which production of wood stains, and the dyeing of textiles withoutshrinkage are examples; (3) Where the oily or fatty .material is avehicle in which some other substance is dissolved or dispersed, ofwhich colored rubber solvents are an example.

The oil soluble colors which are at present available for the generalpurposes outlined above are limited in number and shades of coloravailable. Moreover, a great many of them possess very inferior lightresisting properties and as a class they are quite expensive in relationto their iields of usage. They are particularly expensive in comparisonwith the cost of many of the water soluble dyestuffs. All of thesefactors have limit ed the fields of usage of oil soluble colors verymaterially. I,

On the other hand, the water soluble dyestufis can be obtained in almostan indefinite variety of colors and shades and with varying degrees oflight fastness. These water soluble dyestuffs, however, are not solublein oils, fats, waxes or the like, nor have any means or methodsheretofore been known by which they could be dispersed throughout oilsand the like.

Therefore, one object of this invention is to provide a new series ofdyestuffs which are not only water soluble, but which are likewisesoluble in oils, fats, waxes and the like.

Another object of the invention is to provide a method of establishing astable dispersion of oil insoluble dyestuffs throughout oils, fats,waxes and the like.

Another object of the invention is to provide a method of dispersingwater soluble dyestuffs in oily bodies.

Another object of the invention is to provide a new series of dyestuflswhich give optically clear dispersions in oily bodies.-

Another object of the invention is to provide a new colloidalconstruction of matter capable of selective color carrying properties.

I have determined that it is possible to disperse water soluble, oilinsoluble dyestuffs 10 throughout oily bodies by incorporating thedyestuff with oil soluble materials which are also colloidally watersoluble.

Otherwise expressed, I have discovered that there exist a class ofcolloidally water soluble 1 bodies which can be dissolved in oil andwill carry into oil solution, water soluble, oil insoluble dyestuffs.This can be accomplished by thoroughly incorporating the dyestufl? withappropriate quantities of water and the oil soluble dispersing agent, bygrinding, heating or stirring, and either dissolving the resultingproduct in gasoline or oil, or heating the product until the water hasbeen driven oil and dissolving the-dry product. Clear solutions areobtained from which the color cannot usually be removed by settling,filtration or washing with water.

Dispersing agents suitable for use with mixes containing water mustpossess the power of absorbing a substantial quentity of water withoutseparating from it and without losing the essential property ofdissolving in oil. For use by either method the dispersing agents shouldpossess sufflcient attraction for water soluble dyestufis to enable thedispersing agent to carry the dyestuii into oil solution.

Some of the materials which possess these properties to a greater orlesser degree and can be used successfully are the various sulfonatedfatty oil aromatic compounds similar to the original Twitchell reagentcompound, the oil soluble sulfonated vegetable oils, the synthetic fatsplitting agents such as the hydrogenated and sulfonated naphthalene andanthracene compounds, the various oil soluble soaps prepared from fattyacids and basic organic nitrogen compounds as exemplified bytriethanolamine, stearate and oleate and the naphthenic acids and theoxidized or oxidized and sulfonated products derived from petroleum, andthe similar products derived from brown coal tar and similar products.

However, by far the best dispersing agents are the oil soluble mineraloil sulfonates, usually derived from petroleum. The mineral oilsulfonates are produced commercially as by=products of the layer.

operation of refining petroleum to produce the medicinal white oils orlight colored technical oils by treating the petroleum or fractionsthereof with fuming sulfuric acid and/or sulfur trioxide.

After the sulfonation two layers are formed, the A layer or oil layer,and the 3 layer or sludge The most readily oil soluble mineral oilsulfonates are extracted from the A layer by the well knownPetrofI-Humphries process. The products produced commercially by thePetroi'f- Humphries process contained numerous impurities and the purermineral oil sulfonates can be obtained in a more pure form by additionalalcoholic extractions as disclosed, in the Fischer and Reddish PatentNo. 1,703,838, issued February 26, 1929.

Generally speaking, the products obtained by the Petrofi-Humphriesprocess are called mahogany sulfonates or mahogany soap and the purifiedproduct for convenience is termed true mahogany in that it possesses anddisplays colloidal powers and behavior somewhat diflerent from theimpure product.

The oil soluble mineral oil sulfonates or mahogany sulfonates arecolloidally soluble in water, soluble in all proportions in oil, andeither alone or mixed with oil have the capacity to absorb approximatelytheir own weight of water and still retain their oil solubility. Theyalso seem to possess a particular afilnity for the water solubledyestufis in the absence of water almost appearing to act as solventsfor the dyestufl, and. therefore these mahogany sulfonates, andparticularly true mahogany, are the most desirable dispersing agents forpracticing these methods of coloring oily, fatty and waxy materials.

The most desirable method of using the dispersing agents is dependentupon the nature and characteristics of the particular dyestufl, beingused. If the dyestufi dissolves easily in water without forming stickyagglomerates it is desirable to first dissolve the dyestuff in the waterand then add the dispersi: g agent to the water solution. In case thedyestuif tends to become gummy when dissolved in a small amount ofwater, it is preferable to first grind the dyestufi with the dispersingagent and then gradually add water.

In case it is desirable to avoid dehydration, the amount of water whichcan be used is dependent upon the ability of the particular dispersingagent to absorb water and carry it into oil. If too great a quantity ofwater is used the resulting solution will be cloudy and will slowlysettle. The amount ofdyestufi which can be used is governed by thesolubility of the particular dyestuflf in water. If too great a quantityis used the undissolved particles will settle out of solution.

In some cases the mixes containing water have been found to be morestable than the dehydrated mixes while with other dyes and oils thedehydrated mixes are more desirable and often from the nature of thematerial are necessary.

The following examples indicate several convenient and efiective ways ofcarrying out my invention, but it is to be understood that the inventionis not limited thereto.

Example 1 Two parts of patent blue A, Color Index #714 are ground with amixture of 10 parts of purified oil soluble mineral oil sulfonate and 12parts of white oil. Ten parts of water are added with thorough mixing.One part of this mixture dissolved in parts of gasoline gives a deep'blue clear solution, the actual dyestufi concentration beingfifty-eight parts in 100,000. Thiscan be diluted to give a dyestuilfconcentration of one part in 100,000 parts of gasoline, which stillgives a sufllcient depth of blue to distinctly identify a gasoline.

Example 2 Two parts of acid violet, Color Index #698, are dissolved in20 parts of water and 44 parts of a mixture of 20 parts of purified oilsoluble mineral oil sulfonate and 24 parts of white oil are stirred inthoroughly and heated until the water is driven out. One part of thepaste thus formed is dissolved in 2000 parts of gasoline giving adistinctive purple color. Water can be added or the gasoline filteredthrough filter paper without aifecting the color.

Example 3 Example 4 Two parts of direct black CxR are dissolved in 20parts of water and 44 parts of a mixture of 20 parts of purified oilsoluble sulfonate and 24 parts of mineral oil. This paste is dissolvedin gasoline to give a black in concentrated solution and metallicappearance in dilute solution.

Example 5 Coloring of lubricating oils.

From A; to 1% of any of the dyestuffs pastes whose preparations aredescribed in Examples 1, 2 and 3, can be used to color oils such asmetor oils, for identification purposes. The dyes aremost effective whenused on the lighter colored oils and greater quantities are necessarywith the greener oils.

Example 6 From 1 to 2% of patent blue -A paste prepared as described inExample 1, is dissolved ,in nitrocellulose lacquer. A transparent bluefilm is formed on drying without precipitation of dye or cloudiness.

Example 7 Two parts of the paste dispersions'described in Examples 1,' 2and 3 are dissolved in'100 parts of dry cleaning naphtha. White silk istinted blue, violet and. pink respectively, after 1 to 2 minutesimmersion. .05 parts of acetic acid added to the solutions produces adeeper color. The

dyeings produced in this manner are not fast to washing but are suitablefor tinting goods in the dry cleaning process which are not to besubjected to washing.

Example 8 Four parts of acid green paste dissolved in 100 parts ofturpentine or petroleum solvent will stain wood a light green which isnot removed by water.

Example 9 Two parts of acid green are incorporated in 40 parts oftriethanolamine oleate and 10 parts or water added.- The mixture isdissolved in gasoline and gives a green solution.

Example 10 Two parts of methyl violet are ground in 40 parts ofsynthetic fat splitter, consisting mainly of hydrogenated, sulfonated,anthracene, which has been neutralized with a suitable alkali. Fifteenparts of water are incorporated in the'mixture. The resulting pastedissolved slowly in gasoline to give a violet solution.

Throughout this description and throughout the following claims, theterms oil and oil solubl have been used to contrast with water and watersoluble. It is to be understood, however, that the term oil is meant toinclude oils, fats, greases, waxes and similar bodies which are solublein oil or mixable with oil and is meant to include gasoline, benzine,naphtha, white 011, lubricating oil, vasoline, parafiln oil, allpetroleum products, stearic acid, vegetable oils, animal oils and thelike.

It is to be understood that the invention is not limited to specificfeatures and details herein described but can be carried out in otherways without departure from its spirit as defined by the followingclaims.

Having described my invention, I desire to be limited only by thefollowing claims:

1. The method of preparing oil insoluble dyestufis for dispersionthroughout oil, said method, comprising, mixing said dyestufis with oilsoluble mineral oil sulfonates in the presence of water, dehydrating theresulting body.

2. The method of dispersing oil insoluble dyestufis throughout oil, saidmethod, comprising, mixing said dyestuffs with oil soluble mineral oilsultonates in the presence of water, dehydrating the resulting body, andthen dissolving the mixture in oil.

3. A new dyestuif adapted to color oils, said dyestufl comprising anintimate admixture of mahogany sulfonic bodies and a water solubledyestuff.

4. The method of coloring oils with dyestuffs normally water soluble butoil insoluble, said method, comprising, forming an intimate admixture ofa dyestufi of the class specified, water, and mahogany sulfonic bodies,and thereafter dissolving said admixture in the oil to be colored.

5. A new dyestufl adapted to color oils, said dyestufl! comprising anintimate admixture of mahogany sulfonic bodies, moisture, and a watersoluble dyestufl.

. JOSEPH STRAUS.

